1. Field of the Invention
The present invention relates to a radio apparatus and a battery capacity notification method, and more specifically, to a portable telephone provided with imaging function and notifying a call destination of the decrease in the battery capacity of the portable telephone.
2. Description of the Related Art
A portable telephone including a video telephone function is known as a portable telephone set provided with a communication function of image information. This portable telephone having a video telephone function uses a battery that is rechargeable for its power supply. The portable telephone is capable of performing communication functions even while moving. On the other hand, the portable telephone is restricted in terms of usable time. Therefore, the battery capacity level is displayed to the user of the portable telephone and the remaining amount of the battery life is indicated to the user. When the battery capacity decreases, the portable telephone outputs a battery capacity decrease alarm and notifies the user that the power supply is turned off and the line is disconnected during a call.
However, there are problems in the above-described portable telephone. It is a first problem that the above technique has no means for being aware of the remaining amount of the battery, that is, battery capacity level of the portable telephone from the call destination. Therefore, during a call, even when the battery capacity decreases, it is impossible for the call destination to give an alarm to the portable telephone. Further, it is a second problem that, when the battery capacity decrease alarm of the portable telephone occurs, only the alarm sound is communicated to the call destination. The call destination has no means for judging whether the alarm sound is the battery capacity decrease alarm or not. Like the above-described first problem, therefore, even when the battery capacity decreases during the call, it is impossible for the call destination to give the alarm to the portable telephone.